You could call it the blink of an eye but, realistically, even that takes about eight times longer from start to finish.

That tiniest of split-seconds was all that separated Thomas Barr from taking a sensational bronze medal in the 400m hurdles final in Rio’s Olympic Stadium on Thursday afternoon.

The Waterford native arrived knowing that if he had produced the run of a lifetime two nights ago just to qualify, he would need to go even better again to give himself a shot at the medals.

He did exactly that and more. His time, a stunning 47.97, was the fastest of his career by more than four-tenths of a second; a new national record for the second time in three days.

Source: David Davies

Source: Martin Meissner

In each of the last three Olympics, it would have been good enough for him to take a place on the podium — silver in Athens and Beijing, and bronze in London four years ago.

A remarkable triumph by the first Irish man to contest an Olympic sprint final since Bob Tisdall took gold in the same event at the Los Angeles Games in 1932.

A performance that will set him apart as one of Ireland’s track greats and, at the age of just 24, point to the most exciting future of endless possibilities.

But then those bittersweet thoughts of what might have been.

America’s Kerron Clement took gold with a season’s best of his own, 47.73, with Kenya’s Boniface Tumuti also setting a new national record of 47.78 on his way to silver.

A new national record too for Yasmani Copello — Cuban by birth but representing Turkey — the man closest to Barr at the line as he dipped in 47.92.

Those margins.

Source: Morgan Treacy

With none of the medallists from last year’s world championship final, this race was already wide open as the athletes took their place at the start line. The organisers’ misguided attempts to sell more tickets for the morning track and field sessions meant that this final took place at noon local time, the midday sun turning up the heat as it beat down on the track.

It didn’t seem to bother Barr, who swigged from his water bottle and couldn’t help but grin as he was introduced to the crowd, taking his place as one of the top eight hurdlers in the world over this distance.

That number quickly became seven as pre-race favourite and London bronze medallist, Javier Culson of Puerto Rico, broke too quickly from the blocks beside Barr. A false start and, under the unforgiving rules, automatic disqualification.

When they got away the second time, Barr looked to hit his stride quickly. After a season wracked by injury — remember, he spent 11 weeks off the track with a hip problem before returning for the National Championships in June — he has timed his return to form perfectly.

The most intriguing thing here is his potential to go quicker again. He was fluid over the hurdles, though might feel that he could have been a fraction faster in getting to some of them, split-seconds sacrificed in the pursuit of careful precision.

And as the field turned for home, Clement turned the screw, trying to put daylight between himself and the chasing pack as he closed in on the gold that has been so elusive for him.

Source: Morgan Treacy

Source: Morgan Treacy

Barr had every chance, his powerful finishing kick unquestionably his strongest asset. He clawed back the ground, stride by stride, but the line came a moment too soon for him.

Had this race been 10 metres longer, we would surely be celebrating the third Irish medal of this rollercoaster Olympics.

But if just getting to the final was bonus territory, Barr took full advantage with one of the all-time great Irish performances on the track, and that can never be taken away from him.